Elevator door carrying mechanism



Sept. 22, 1959 Filed Jan. 6, 1956 J. H. BORDEN 2,905,463

ELEVATOR DOOR CARRYING MECHANISM 4 Sheets-Sheet 1 AWN-5.;

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JOSEPH H BORDE /V Sept. 22, 1959 J. H. BORDEN 2,905,463 v ELEVATOR DOR CARRYING MECHANISM Filed Jan. 6, 1956 4 sheets-sheet 2 N \f\ v 1 W :s n

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JOSZH H 50H05 /V J. H. BORDEN 2,905,463

ELEvAToR DooR CARRYING MECHANISM Sept. 22, 1959 4 Sheets-Sheet 3 Filed Jan. 6, 1956 IN VEN TOR.

JSEPH H BORDE /V Sept. 22, 1959 J. H. BORDEN 2,905,463

ELEVATOR DOOR CARRYING MECHANISM med Jan. e, 195e 4 sheets-sheet 4 IN VEN TOR.

L/OSg/YDH H BORDE/V MZZM A rae/VE s United States ELEVATOR 'DOOR CARRYING MECHANISM Application January 6, 1956, Serial No. '557,682

4 Claims. (Cl. 268-49) The-car doors andhatchway doors of passenger elevator systems are hung from carriages whichtravel back and forth on rails as the doors open and close. The mechanism that opens and closes the doors is usually attached to the carriages at points above the rails, the centerof mass of each door being far below the point at which the' opening and closing mechanism acts. The inertia of the door therefore tends to rock the door and its carriage each time themechanism starts or stops an opening movement or a closing movement;

To avoid the banging and wear and liability to get out of order that was caused by such tendency to rock it-'has been the practice heretofore to minimize thetendency byv employing opening and closing mechanism that starts and stops the door so gradually that the eifect of gravity has been sucient to overcome the tendency to rock. and to' thus keep the carriage wheels from being lifted fromthe rail upon which they roll.

Much inventive ingenuity has been devoted to means for expediting the functioning of passenger elevator mechanisms. High speed operation is an important goal not only because it gives better service to elevator patrons but also because it often enables four or live elevators totake care of requirements that would employ six or eight slowly functioning elevators.

Some of the time saved by expensive mechanism ingeniously designed to achieve quick starting of cars and swift acceleration and deceleration between oors is lost at every stop by slow opening and closing of doors.

It is an object of this invention to provide an improved carriage for elevator` doors which makes it possible to open and close the doors more expeditiously.

Another object is to provide an improved carriage which is capable of carrying elevator doors smoothly and silently when moved by powerful quick starting and quick stopping motors.

Another object is the provision of a carriage for elevaatent tor doors which is capable of carrying doors that are high and narrow through quick movements with maximum silence land minimum friction and wear.

Other objects and many advantages of the invention will be apparent upon perusal of the following description, illustrated by the accompanying drawings wherein:

Fig. I is a view in perspective of apparatus for moving elevator doors of the so-called center opening type, which apparatus includes two units of the elevator door carrying mechanism of my invention, the doors being shown as closed;

Fig. II is a view of the same apparatus with the doors open;

Fig. III is an enlarged elevational view showing one unit of the elevator door carrying mechanism of my invention as seen from the rear with respect to Figs. I and II;

Fig. IV is a sectional View taken as indicated by the line lV-IV of Fig. III;

Fig. V is a detailed elevational View of the parts illustrated in IV, some parts being broken away and;

ice

Fig. VI is an elevational view showing the elevator door carrying mechanism of myk invention as applied to apparatusof the so-called side opening type.

These drawings and the following description are exemplary only and are not intended to impose limitations on the scope of theinvention.

In the form of device illustrated in Figs. I, Il, III, lV and V the entire door openingtand closing apparatus iS mounted upon a plate 1 which may be anelement of an elevator car. structure. The plate 1 has a rearwardly extending ange 2 along its upper edge on whichare mounted a motor 3 and a control box 4. The motor 3 is reversible and acts through a belt 5 and a large pulley 6 toturn a sheave 7 around which is looped a cable 8 which also is looped around a secondsheave 9 that is connectedby meansof a chain 10 and a sprocket 1l` to controls within the control box 4.

Fixed to the face of the plate 1 adjacent its lower edge is a row of brackets 12 which support arail 13 having a rounded top 14 and a ilat bottom 15, as indicated in Fig. 1V. A pair of doors 16 and 17 is hung from a pair of carriage bodies 18 and 19 formed of short legths of shallow channels. Studs 20, 21, 22 and 23 are -ixed to and extend into the channels and constitute stubaxles for carriage wheels 24, 25, 26 and 27 having concave treads which roll upon the rounded top of the rail13.

An arm `28 extends rigidly upward from the carriage body 18 andis attached at its upper end to the lower lay ofthe cable 8, anda somewhat longer arm 29 extends rigidly upwardly from the carriage body 19, the longer arm 29 being attached at its upper endto the upper lay of the cable 8. Hence when the motor 3 turns in one direction'the -upper ends of the arms 28 and 29 will be pulled away from each other and the doors` 16 and 17 will be caused to open, and when the motor 3 subsequently turns in the opposite direction the arms 28 and 29' will be pulled toward each other and the doors 16 and 17 will be vcaused to close.

TheA doors-16 and 17 are shown in the drawings with their lower parts broken away. Actually the centers of mass of the heavy doors 16 and 17 are far below the wheels 2425, 26' and 27 and forces applied to the upper ends of` they arms 28 and 29 tend to rock the doors about the fulc'rav at the wheels. Suchrrocking can be, and heretofore has been, avoided by applying weak forces which become effective so gradually that actual rocking is prevented by the downward pull of gravity. The extent of rocking that occurs when the closing or opening movementsof the-doors are stopped suddenly can be and heretofore has been limited by including stops or guards,

in-.the apparatus. Y ASuch stops or guards have been made in theV form of rollers which engage tightly against fixed surfaces only after undesirable rocking has started. Continous, tight engagement of'stops or guards hasheretofore been regarded as not feasible because of the-binding and friction resulting-from such continuous tight engagement.

The instant invention makes it practicable entirely to avoid rocking, even of long and narrow doors moved quickly by powerful motors. Rocking is avoided by supplementing the effect of gravity with additional downwardly acting force, the effect of which may be several times ask greatV as the effect of gravity but which nevertheless adds little or nothing to the inertia of the-doors. Thisliighly desirable result is accomplished moreover while permitting the carriage wheels 24', 2526 and 27 to roll over humps and depressions along the rail 13, or around the wheels themselves, without excess binding, theI supplemental` force that acts with gravity to hold the carriage wheelsy in continuous tight engagement with the rail 13 being a yieldable force.

The yieldable; supplemental force may be applied' in various Ways Abut for eiectiveness in the particular apparatus described above I prefer to apply it by means of helical expansive springs 31 and 32 acting horizontally against vertical arms of bell crank levers 35, 36, 37 and 38, the fulcra of which are axles 39, 40, 41 and 42 of rollers 43, 44, 45 and 46 which bear upwardly against the at bottom of the rail 13. Horizontal arms of the bell crank levers 35, 36, 37 and 38 press downwardly upon posts 47 and 48 which are fixed to the carriage bodies 18 and 19, the lower portions of the posts furnishing abutments for ends of the helical expansive springs.

The springs, bell crank levers, rollers and posts being identical, only one of the devices will be described in detail. As illustrated, each of the posts is solid, while each of the bell crank levers is fabricated of at parallel spaced members 51 connected by three pins, one of which also functions as a power pivot S2 to which the force exerted by one of the springs is applied, another of which functions as the fulcrum pivot as well as the axle of one of the rollers, while the third functions as the load pivot S4, which supplements gravity in holding the door against tendency to rock.

Surrounding each power pivot pin 52 is a collar 55 having a flat side against which one end of the spring 31 bears, The other end of the spring bears against the head 56 of a stud 57 whose shaft forms a guide extending part way through the spring. The head 56 of the stud is guided in an opening in the post 47, and the compression of the spring can be adjusted by means of a screw 58 provided with a lock nut 59. By backing up the screws 58 the rollers 43 and 44 can be moved away from the wheels 24 and 25 far enough to permit the carriage to be easily assembled with the rail 13. The screws then can be adjusted to permit the springs to exert their full expansive force, which may be such as to multiply the force with which the carriage wheels 24 and 25 are held against the rail 13. While a door Weighing, e.g., l() pounds would press each wheel against the rail with a force of only 5() pounds the springs may augment the force holding each wheel against the rail to 100 pounds or 200 pounds or to any extent necessary to prevent rocking even though the power of the motor, the speed of the door and the acceleration and deceleration in starting and stopping be doubled or tripled.

In the apparatus illustrated in Fig. VI the carriage body 19a has one arm 29a attached to the upper lay of a cable 8a to move the door 17a in the manner above described. The carriage body 19a has another upright arm 60 which is attached to the lower lay of a cable 61 that is looped around sheaves 62 and 63 that are mounted on a superstructure 64 secured upon a carriage body 18a.

vThe upper lay of the cable is attached to the plate 1a on which the motor 3a, control box 4a, etc. are mounted. Thus when the upright arm 60 pulls the lower lay of the cable 61 in either direction the sheaves 62 and 63 move in the same direction as that in which the upright arm 60 is moving but at half the speed.

The carriage bodies 18a and 19a are supported by separate rails and their planes of movement overlap. Ihe doors themselves overlap also when they are open.

The means employed to permit the doors to be opened and closed speedily without rocking are like the means described in detail above as applied to center opening doors and it is believed that another description thereof would be unnecessarily repetitions.

My invention as applied either to center opening doors or to side opening doors insures smooth highspeed operation which can save thousands of passenger-minutes everyday in every passenger elevator system in which the invention is employed. Moreover it enables doors to be made long and narrow and enables door moving mechanism to be designed, located and hooked up to door structures in the most economical and eiective manner unhampered by considerations of inertia, If, for example, the additional vertical force applied in accordance with my invention to constantly hold the carriage wheels in tight engagement with the rail amounts to some pounds, the horizontal force exerted by the motor to move the door structure may be doubled or tripled from some 30 or 40 pounds to 90 or- 120 pounds, even though the horizontal force acts at a point remote from the center of mass of the door structure.

The invention is susceptible to variations within the spirit and scope of the subjoined claims.

Having described the invention, I claim:

l. In an elevator door carrying mechanism, a rail having parallel upper and lower surfaces, a carriage having a pair of wheels to roll along the upper surface of said rail, an elevator car door depending from said carriage, a motor, means operatively connecting said motor to said carriage at a point remote from the center of mass of said door, whereby accelerating or decelerating forces applied to such point so remote from said center of mass tend to rock said carriage and door and thereby tend to lift one of said wheels from said rail, a roller engaging with the lower surface of said rail, a bell crank lever pivoted at the axis of said roller and having a vertically extending arm and a horizontally extending arm, and a spring acting horizontally between said carriage and said vertically extending arm to cause said horizontally extending arm to exert a yieldable downwardly directed force upon said carriage and thereby hold said carriage against rocking.

2. In an elevator door carrying mechanism, a rail having parallel upper and lower surfaces, a carriage having a pair of wheels to roll along the upper surfaces of said rail, an elevator car door depending from said carriage, a motor, means operatively connecting said motor to said carriage at a point remote from the center of mass of said door, whereby accelerating or decelerating forces applied at such point so remote from said center of mass tend to rock said carriage and door and thereby tend to lift one of said wheels from said rail, a roller engaging with the lower surface of said rail, Vand a spring so connected with said carriage and said roller as to exert a yieldable downward force on said carriage and to react upwardly on said roller, said means comprising a pair of rollers engaging with the lower surface of said rail, a pair of bell crank levers each pivoted at the axis or" one of said rollers and each having a vertically extending arm and a horizontally extending arm, and an expansive spring exerting a yieldable force horizontally upon each said vertically extending arm thereby causing each said horizontally extending arm to act downwardly upon said carriage and thus hold said carriage against rocking. i

3. In an elevator door carrying mechanism, a rail having parallel upper and lower surfaces, the upper surface being rounded, a carriage having a pair of Wheels having concave treads to roll along the upper surfaces of said rail, an elevator car door depending from said carriage, a motor, means operatively connecting said motor to said carriage at a point remote from the center of mass of said door, whereby accelerating or decelerating forces applied at such point so remote from said center of mass tend to rock said carriage and door and thereby tend to lift one of said wheels from said rail, a roller engaging with the lower surface of said rail, and a spring so connected with said carriage and said roller as to exert a yieldable downward force on said carriage and to react upwardly on said roller, said means comprising a pair of rollers engaging with the lower surface of said rail, a pair of bell crank levers each pivoted at the axis of one of said rollers and each having a vertically extending arm and a horizontally extending arm, and an expansive spring exerting a yieldable force horizontally upon each said vertically extending arm thereby causing each said horizontally extending arm to act downwardly upon said carriage and thus hold said carriage against rocking.

4. In an elevator door carrying mechanism, in combination, a substantially horizontal supporting rail, a pair of wheels rotatable on axes that are fixed With'respect to an elevator door structure, said Wheels being adapted to and mounted to roll `along the top of said substantially horizontal supporting rail, and means to counteract tendencies of acceleration and deceleration of said door, when quickly opened or closed, to lift said Wheels from said rail, said means comprising a bell crank lever having a laterally extending arm pivoted to such elevator door structure at a pivot point that is xed with respect to such elevator door structure, a roller which engages and rolls along a downwardly facing surface that is xed in respect of said rail, said bell crank lever having its fulcrum pivot on the axis of said roller, a horizontally acting spring, said bell crank lever having an approximately vertically extending arm which is pivotally connected to one end of said horizontally acting spring, the other end of said horizontally acting spring being fastened to such elevator door structure at a point fixed with respect to such elevator door structure.

References Cited in the tile of this patent UNITED STATES PATENTS 1,329,326 Parsons Jan. 27, 1920 2,235,381 McCormick Mar. 18, 1941 2,318,090 McCormick May 4, 1943 2,430,729 Negri NOV. 11, 1947 2,572,196 Raque Oct. 23, 1951 2,574,496 Pomeroy et al. Nov. 13, 1951 FOREIGN PATENTS 126,362 Australia Dec. 17, 1947 659,625 Great Britain Oct. 24, 1951 

